This invention relates generally to an antenna assembly and, more particularly, to a collapsible, steerable antenna assembly configured for rapid deployment.
Traditionally, to receive an adequate signal from a communication satellite, an antenna had to be securely fitted to a rigid mount which was adjustable in both azimuth and elevation. Later, antennas began being mounted on moving vehicles. These antenna systems were required to be adjustable in elevation sufficiently to suit the latitude of the vehicle. In addition, portable antenna systems also began to develop. These portable systems were also required to be adjustable in elevation sufficient to suit the latitude of the ground at which they were located.
The use of portable antenna systems and other electronic equipment in the field today often requires the positioning of an antenna of substantial size, in order to prevent terrestrial interference and interference from other satellites with signal beings radiated or received by the antenna. In addition, the antenna and its support should be sufficiently compact in the stowed position, so as to not interfere with mobility of the antenna in the field.
Portable antenna systems of the general type mentioned above have been built in the past, but suffer from several disadvantages. These include excessive assembly time, a large number of separate pieces, complex assembly procedures which lead to a loss of parts and unreliability, difficulty of assembly, and the requirement of multiple operators to assemble and disassemble the system.
In addition, these systems have been designed with the primary goal of breaking the unit down into multiple light-weight shipping containers that meet the maximum standards for lower lobe airline shipping. This increases the complexity and lengthens the assembly time of the antenna.
Further, past systems have proved inadequate in their ability to minimize distortion in the antenna dish of the system, due to either assembly technique or parametric distortion under the weight of the dish and other system components.
It is desirable for antenna system components to be as adjustable as possible for positioning and alignment efficiency. There is a continuing need for an antenna system that is highly accurate, yet has high modularity and portability, while remaining simple to assembly.
Accordingly, those skilled in the art have long recognized the need for a collapsible, steerable antenna assembly configured for rapid deployment. The present invention clearly fulfills these and other needs.
Briefly, and in general terms, the present invention resolves the above and other problems by providing a back frame assembly that is configured to minimize parametric distortions in an antenna dish of an antenna system by supporting the shape of the antenna dish. The back frame assembly includes a center frame, a template assembly, and a feed leg mount. The center frame selectively engages the controller assembly and the antenna dish. The center frame includes a brace structure and a plurality of connection arms. The template assembly attaches to the center frame and includes a plurality of leaves that engage the antenna dish and hinge at an intersection point. The plurality of leaves have a folded transportation state and an unfolded operational state. The feed leg mount attaches to the center frame. Additionally, the feed leg mount connects to and supports the weight of a main feed leg, antenna horn, and possibly an amplifier in order to minimize distortion of the antenna dish due to the weight of a main feed leg, antenna horn, and possibly an amplifier.
In a preferred embodiment of the present invention, the brace structure of the center frame includes four legs, four connection arms, and is substantially diamond shaped in configuration. The connection arms of the center frame extend from the legs of the diamond shaped brace structure and attach directly to the antenna dish. In another preferred aspect of the present invention, the template assembly includes the same number of leaves as there are sections of the dish antenna. Preferably, the back frame assembly includes cross struts to more efficiently bear lateral stresses. Additionally, the feed leg mount of the back frame preferably is rotatably attached to the feed leg of an antenna system.
In another preferred aspect of the present invention, the back frame assembly includes a protractor and adjustment screw for transmission beam angle reference to insure precise elevation alignment in cases where the backframe and antenna assembly are to be set up with a manual steering head as in fixed antenna installations. In yet another preferred aspect of the present invention, the back frame assembly includes a protractor and adjustment screw for transmission beam angle reference to the polarity tombstone controller to insure precise alignment of the axis of polarity rotation and the antenna""s transmission beam. The back frame assembly includes an electronic compass to insure precise azimuth alignment of the transmission beam axis. The back frame assembly includes an electronic level meter to insure precise elevation alignment of the transmission beam axis.
Briefly, and in general terms, the present invention resolves the above and other problems by providing a transmission field sighting device for sighting potential obstructions in a transmission beam from an antenna dish in an antenna system. The sighting device includes a sighting tube and an attachment bracket. The sighting tube aligns with the transmission beam axis from the antenna dish. The attachment bracket secures the sighting tube to the antenna system. In this manner, viewing through the sighting tube of the transmission field sighting device allows determination of whether obstructions exist in the transmission beam from the antenna dish, thereby facilitating obstruction-free positioning and orientation of the antenna system.
In a preferred embodiment of the present invention, the sighting tube of the transmission field sighting device is an empty tube. In another embodiment of the transmissions field sighting device, the device is a low power telescope with a crosshair reticule. The present invention is preferably utilized in an offset antenna system that has a transmission beam axis that is offset from the centerpoint of illumination axis. Preferably, the transmission field sighting device attaches to a back frame assembly of the antenna system.
In one preferred embodiment of the present invention, the dish assembly, back frame assembly, rotary steering assembly, and collapsible mount assembly are deployable by a single person. Preferably, the steerable antenna assembly is collapsible, rapidly deployable, has very few parts, and is inexpensive compared to other types of known antenna systems.
Other features and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, which illustrate by way of example, the features of the present invention.